[{"_id":0,"name":"name","description":"description","products":[{"productName":"productName","price":0,"thumbnail":"thumbnail","description":"description"}]},{"_id":1,"name":"name1","description":"description1","products":[{"productName":"productName1","price":1,"thumbnail":"thumbnail1","description":"description1"}]}]

db.collection.find({"_id":0,"products.productName":"productName"})